Hydraulically elevatable seat for chairs



June 20, 1961 J. D. GOODING ETAL 2,989,279

HYDRAULICALLY ELEVATABLE SEAT FOR CHAIRS 3 Sheets-Sheet 1 Filed July 14, 1958 INVENTORS JQGQD. GUOO/A G #0694 0. JE/VN/NGS JG.

June 20, 1961 J. D. GOODING ETAL 2,989,279

HYDRAULICALLY ELEVATABLE SEAT FOR CHAIRS Filed July 14, 1958 s Sheets-Sheet 2 FIG. 2. J me 0. GOOD/AG #49? C. JEA/N/NGS, JB.

INVENTORS Y b m f z June 20, 1961 J. D. GOODING ETAL 2,989,279

HYDRAULICALLY ELEVATABLE SEAT FOR CHAIRS Filed July 14, 1958 5 Sheets-Sheet 3 FIG. 5.

United States Patent 2,989,279 HYDRAULICALLY ELEVATABLE SEAT FOR CHAIRS v Jack D. Gooding and Harry C. Jennings, In, Los Angeles,

Calif., assignors to Everest & Jennings, Inc., Los Angeles, Calif., a corporation of California Filed July 14, 1958, Ser. No. 748,452 Claims. (Cl. 155-94) This invention relates to elevatable seats for chairs.

Explanatory of the present invention, it is frequently desirable to equip a collapsible invalid wheel chair with a seat-supporting structure and a seat which can be raised and lowered relatively thereto so that the height of the invalid supported on the seat can be adjusted as desired. Usually, such collapsible wheel chairs have a pair of opposed seat. rails at the top of an X-brace which enables the side frames of the wheel chair to collapse towards each other. In the conventional wheel chair a flexible and usually fabric seat is connected to the seat rails so as to be suspended therebetween. The flexibility of the seat does not interfere with movements of the seat rails toward and away from each other.

In providing such a Wheel chair or collapsible chair with an elevatable seat, it is desirable to removably position the seat-supporting structure on these seat rails so that the elevatable seat can be removed therefrom whenever it is desired to collapse the chair. At the same time it is also desirable to have the seat-supporting structure adequately locked on the seat rails when they are in extended position to avoid any tendency of the removable seat-supporting structure to tip in response to movements of the invalid seated thereon.

An object of the present invention is to provide a hydraulically elevatable seat and seat-supporting structure therefor which can be detachably positioned on the seat rails at the sides of a collapsible chair and which is so designed that when the chair is extended with the seatsupporting structure positioned thereon the seat-supporting structure will be locked adequately against tipping.

Another object of the invention is to provide a hydraulically elevatable seat which can be manually raised or lowered by the invalid while seated on the seat so that hisfheight with respect to the chair can be varied at will.

A further object of the invention is to provide a hydraulically elevatable seat wherein a piston and cylinder are disposed between the seat and the seat-supporting structure and are actuated by a pump having a reciprocable piston that is connected to a telescopic liquid reservoir, and to provide means for elfecting a release of the liquid from the pump and cylinder back to the reservoir which is controllable by the pump actuating means and actuated when the pump actuating means exceeds its normal intake stroke. In this manner, a release of fluid and consequent lowering of the seat can at all times be accomplished in that it is impossible to create a hydraulic lock in the system which would lock the seat in its uppermost position.

Another object of the invention is to provide a hydraulically elevatable seat having the above-mentioned characteristics wherein the actuating handle for manually operating the pump is composed of two parts pivotally connected together, and a third part telescopically mounted upon one of the pivoted parts and capable of assuming a position telescoping onto the other of the pivoted parts to rigidly lock the pivoted parts together during pumping operation. However, when the seat has reached the desired position, by a simple telescopic movement the third part may be caused to assume a position wholly on only one of the parts so that it may be swung into an out-of-the way or unobjectionable position.

With the foregoing and other objects in view, which will be made manifest, in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

FIGURE 1 is a view in side elevation of a hydraulically elevatable seat embodying the present invention;

FIG. 2 is a bottom plan view of the same and illustrating the structure as having been applied to opposed seat rails of a chair;

FIG. 3 is a sectional view taken substantially upon the line 3--3 upon FIG. 2, and illustrating the parts in 'the position assumed to effect a return of :liquid from the cylinder to the reservoir and consequently lower the seat; FIG. 4 is a view similar to FIG. 3, but illustrating the position of parts in the course of elevating the seat; and FIG. 5 is a partial view illustrating the position assumed by the pump handle when used for actuating the pump.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, there is illustrated on FIG. 2, two opposed seat rails 10 and 11 of a collapsible chair. Usually, these seat rails are movable toward and away from each other and are mounted at the tops of the arms of an X-brace, the collapse of which enables the side frames of the chair to move towards each other into collapsed position or away from each other in extended position. Usually the side rails 10 and 11 are formed of cylindrical tubing and in the conventional invalid wheel chair a fabric seat is fastened to the seat rails so as to be suspended-therebe tween. The details of construction of the invalid wheel chair itself form no part of the present invention but may conform to the structures disclosed in United States Letters Patent No. 2,095,411, issued October'l2, 1937, or No. 2,181,420, issued November 28, 1939, to Herbert A. Everest and Harry C. Jennings.

The hydraulically elevatable seat embodying the present invention comprises a supporting frame preferably formed of two overlapped V-shaped pieces of tubing 12 and 13 which are arranged at their crotches so as to'extend around the outer cylinder 14 of a telescopic liquid reservoir. At the ends of the frame formed by the mem bers 12 and 13 there are inverted channels or hooks 15 the outer sides of which, indicated at 16, are semi-cylindrically formed and extend downwardly in fitting engagement with the outer sides of the seat rails 10 and 11 below horizontal diameters of the seat rails. As the weight imposed on the chair by the body of the person seated thereon is effective to urge the seat rails 10 and 11 to separate, this hooking engagement with the outer sides of the seat rails prevents the elevatable seat and associated structure from tipping with respect to the seat rails. However, whenever it is desired to collapse the chair and to remove the hydraulically elevatable seat therefrom, it is merely necessary to movethe seat rails 10 and 11 slightly to wards each other and this will enable the hooked outer side 16 to be lifted off of the seat rails after which the chair may be completely collapsed. I

The crotches of the V-shaped members 12 and 13 are welded or otherwise secured to the outer cylinder. 14 of the reservoir so that this cylinder may be rigidly supported or suspended from the seat rails. The bottom of the outer cylinder is closed by a disc or circular plate 17. Within the outer cylinder there is disposed a telescopic inner cylinder 18 which is secured at its top to a supporting plate 19 that supports the seat 20 which may be suitably upholstered.

Within the inner cylinder 18 there is a sleeve 21 that is threaded onto a packing gland 22 that surrounds a stationary piston rod 23 that is mounted on the closure 17 such as by a cap screw 24. The gland 22 contains packing 25 that can be tightened by a packing nut 26.

The piston rod 23 carries at its top a piston 27 that is preferably equipped with a cup leather or the equivalent indicated at 28. The piston and cup leather are disposed within a cylinder 29 that is supported on the packing gland 22. The space within the cylinder 29 that is above the cup leather 28 and which is indicated at 30, see FIG. 4, constitutes the working part of the cylinder, and if liquid under pressure is forced into this working portion of the cylinder it is apparent that the cylinder 29 and structure thereabove will be forced upwardly. Upward movement of the cylinder, and consequently of the plate 19, causes the inner reservoir cylinder 18 to rise there with relatively to the outer cylinder 14.

As a means for holding the structure supported by the cylinder 29 and consequently the seat 20 from turning or rotating relatively to the supporting frame, toggle links are provided, two of which indicated at 31 and 32, are pivotally connected at their ends to a transversely extending bolt or the equivalent indicated at 33 that extends through a knuckle 34 that is welded or otherwise rigidly secured to the outer reservoir cylinder 14. The other ends of these toggle links are pivotally connected such as by a bolt 35 to the ends of upper toggle links 36 and 37 which are, in turn, pivotally connected to the sides of a block 38 that provides the pump housing. Cap screws or the equivalent indicated at 39 pivotally connect the upper toggle links to the sides of the block. The toggle links permit the seat 20 to rise and fall with respect to the supporting frame provided by the V-shaped members 12 and 13, but in all positions of vertical adjustment the seat 20 is held in proper alignment with respect to the seat rails and 11.

Within the block 38 there is formed a pump cylinder 40 within which is reciprocable a pump piston 41 surrounded by packing 42 that is compressed by a packing nut 43. The pump cylinder 40 communicates through passages 44, 45, and 46 with a dip tube 47 that extends downwardly into the reservoir space within the inner reservoir cylinder 18.

In the passage 45 there are two valve seats for inlet and outlet valves, respectively. The inlet valve is provided by a small ball 48 and the exhaust valve is provided by a somewhat larger ball 49. These valves are urged against their respective seats by coil compression springs 50 and 51, respectively. An idler or motion-transmitter 52 is disposed within the spring 50 and between the two valves. The outlet valve controls flow through a passage 53 that leads to the working space 30 of cylinder 29. Upon reciprocation of the piston 41 liquid in the reservoir within the inner cylinder 18 is drawn upwardly through the dip tube 47, past the inlet valve 48 and into the pump cylinder 40. When the pump piston 41 is forced in the opposite direction fluid taken into the pump cylinder is expelled therefrom past the outlet valve 49 and through passage 53 into the working space 30 in cylinder 29, thus causing the seat 20 to be elevated.

The piston 41 is reciprocated by means of a rockersha ft 54 on which there is a crank 55 to which a link or pitman 56 is pivotally connected at 57. This link or pitman is loosely connected as at 58 to the end of the pump piston 41. The rockershaft 54 has a handle at one end thereof formed by bending the end of the rockershaft to provide a crank 59. Another part of the crank indicated at 61 is pivotally connected to crank 59 as indicated at 62, and a tubular handle 63 constitutes the third part of the crank. This handle has a pin and slot connection 64 with the pivoted part 61. The tubular handle 63 is capable of telescoping on part 61 and onto crank 59 across the pivotal connection 62, thus forming a rigid upwardly extending crank on the rockershaft which can be reciprocated or oscillated by the person seated on seat 20 to effect a reciprocation of pump piston 41. However, after the seat 20 has been adjusted to the desired elevation, the tubular handle 63 can be slid off of crank 59 to occupy a position telescoping solely with part 61. In this position, as illustrated in FIG. 1, the handle 63 may hang vertically downward from crank 59 so as to be out of the way and in an unobjectionable position. It is always available, however, to be returned to its position on crank 59 to change the elevation of seat 20.

A release rod 65 is slidable in block 38 in alignment with the two valves 48 and 49 and the transmitter 52. This release rod is equipped with a cap 66 that is urged by a spring 67 out of engagement with valve 48 or into the position shown in FIG. 4. An actuating handle 68 is pivotally mounted at 69 on block 38 and the top of this actuating handle is arranged in the path of a cross pin 70 on link 56. The lower portion of this handle is arranged in alignment with the cap 66 and can be manually actuated if desired to depress the release rod 65 against the action of spring 67. The parts are so proportioned and designed that the cross pin 70 does not engage thetop of the actuating handle 68 during normal lengths of stroke of piston 41. It is only when piston 41 is withdrawn from its cylinder 40 by rockershaft 54 an abnormal distance in the direction of its intake stroke that the top of the actuating handle 68 is engaged and causes the release rod 65 to be depressed. When the release rod is depressed or moved from right to left, as viewed in FIG. 3, it unseats intake valve 48 which, in turn, engages the idler or transmitter 52 and unseats the outlet valve 49. Thus, when handle 63 is swung forwardly an abnormal distance, communication between the working cylinder 30 and the reservoir inside of cylinder 18 is immediately established allowing liquid to flow from the working portion of cylinder 29 back to the fluid reservoir. This of course permits seat 20 to descend. The reason for having the valves 48 and 49 open at the end of the intake stroke is to prevent a hydraulic lock from being created in the stroke when the seat is in its uppermost position. Thus, if the seat were in its uppermost position limited by the engagement of the top of gland 22 with piston 27 and the cylinder 40 happened to be filled or partially filled with liquid, it would be impossible to bleed liquid back to the reservoir if a release were effected at the end of a power stroke. By having the release effected at the end of the intake stroke, even though the seat is in its uppermost position, it is nevertheless always possible to abnormally withdraw the pump piston 41 from its cylinder 40, cause the release pin 65 to be depressed and to unseat the balls 48 and 49 to bleed back liquid from cylinder 29 to the liquid reservoir.

It will be appreciated from the above-described construction that the present invention enables a hydraulically elevatable seat to be easily and quickly applied to and removed from a collapsible chair structure. When the seat is in applied position on the seat rails it is firmly locked in position thereon. The invalid by merely oscillating handle 63, can raise the seat 20 to the desired elevation, and when he wishes to lower the seat he merely swings handle 63 into an abnormally forward position, that is to a position beyond that required to effect a normal stroke of pump piston 41. Whenever the seat has been adjusted to the desired elevation the handle 63 can be shifted into an out of the way or unobjectionable position as illustrated in FIG. 1 until such time as there is a subsequent occasion to use it.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims.

We claim:

1. A collapsible chair having a pair of side seat rails adapted to spread laterally as the chair is extended, an elevatable seat adapted to be positioned thereon, and hooks associated with the seat at the front and back of each side thereof for supporting the seat on the seat rails and engageable with the under outer sides of the seat rails whereby spreading of the seat rails will engage the hooks in such a manner as to resist lifting or tipping of the seat relatively to the seat rails.

2. A chair seat and supporting structure therefor having a hydraulic piston and cylinder between the seat and the supporting structure, a pump and handle therefor associated with the seat by which fluid under pressure can be supplied to the cylinder to cause the seat to be raised relatively to the supporting structure, means operable by the handle at the end of the normal intake stroke of the pump for releasing pressure from the cylinder to lower the seat relatively to the supporting structure, and means for holding the seat against rotation as it is raised and lowered.

3. A seat and supporting structure therefor having a piston and cylinder therebetween, a telescopic reservoir about the cylinder, a pump connected to the reservoir and discharging into the cylinder to raise the seat relatively to the supporting structure, means for actuating the pump, and means for releasing fluid from the cylinder and pump back to the reservoir to lower the seat operable at the end of the intake stroke of the pump.

4. A seat and supporting structure therefor having a piston and cylinder therebet-ween, a telescopic reservoir about the cylinder, a pump connected to the reservoir and discharging into the cylinder to raise the seat relatively to the supporting structure, means for actuating the pump, intake and exhaust valves between the reservoir and the pump and between the pump and the cylinder respectively, and means for unseating both of said valves operable by the pump-actuating means when the pump-actuating means is moved beyond the end of its normal intake stroke.

5. A chair seat and supporting structure therefor having a hydraulic piston and cylinder between the seat and the supporting structure, a pump having a reciprocable piston for pumping liquid to the cylinder to elevate the chair seat, a reservoir for liquid, valve means permitting flow from the reservoir through the pump to the cylinder upon reciprocation of the piston in the pump but normally preventing fiow in the reverse direction, operating means for reciprocating the piston in the pump, and means operable by moving the operating means beyond the point of commencement of the normal intake stroke of the piston in the pump for causing said valve means to release liquid from the cylinder back to the reservoir to allow the chair seat to descend.

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